/**
 * @file   hello.cpp
 * @author Shao <1248562312@qq.com>
 * @date   Tue Sep 21 20:16:24 2021
 * 
 * @brief  
 * 
 * 
 */

#include <iostream>

/**
 * main function.
 * 
 * @param argc number of shell parameters. 
 * @param argv strings for all parameters. 
 * 
 * @return system signals.
 */
int main(int argc, char* argv[])
{
  /// Just a demo.
  std::cout <<"Hello World!" << std::endl;
  return 0;
};
